Q: Is it possible to fill a black hole? If you were to continuously throw galaxies worth of matter into a black hole, would it ever fill up? And what would theoretically happen if all the matter in the universe was thrown into a single black hole?

A blackhole is already the result of over filling. A blackhole is to mass as the rage virus is to people; throwing more at it just makes it more dangerous. However, unlike zombies, blackholes do eat each other.

The more matter that falls into a blackhole, the bigger the blackhole becomes. For example; the blackhole at the center of our galaxy (Sagittarius A*) has a mass of about 4 million suns, which is already the size of some small galaxies. Small globular clusters anyway.

If all the matter in the universe were chucked into the same giant blackhole you’d have: a really giant blackhole.

21 Responses to Q: Is it possible to fill a black hole? If you were to continuously throw galaxies worth of matter into a black hole, would it ever fill up? And what would theoretically happen if all the matter in the universe was thrown into a single black hole?

The total gravitational attraction of a bunch of mass is a function only of the amount of mass. So whether the mass takes the form of a solar system, or a black hole, or a diffuse gas cloud makes no difference.
Black holes are only impressive if you’re fairy close to them. For example: if the sun were to suddenly collapse into a black hole, the Earth would continue to stay in exactly the same orbit.

A couple of questions, all on the theoretical side (mostly because I doubt we’ve been in existence long enough to observe such things) about black holes:

i) in recent theory, it’s thought that most galaxies start off small and ‘eat’ other galaxies to get bigger. What happens to the black hole in the center of the smaller galaxy? Does it get absorbed into the center of the devouring galaxy, or is it more likely to be a wandering body within the larger galaxy?

ii) The most recently known ‘snack’ galaxy is the aquarius stream, about 70 million years ago (roughly when the earth formed), are there any guesses what happened to its central black hole?

iii) Do all galaxies have a black hole in the center? Is there a theoretical estimate to the minimum galaxy size possible?

i) I’ve heard that the simulations tend to show the black holes finding each other in fairly short order. But, for a while after merging you can have “double yolk” galaxies.
ii) Globular clusters and dwarf galaxies don’t tend to have their own super-massive central black holes. Generally, only large galaxies have central black holes, and when large galaxies merge, they don’t cleanly merge and leave streams, they mix chaotically. So, if there’s a stream of stars in your galaxy that used to be a tiny cluster that was absorbed, it probably didn’t have a central black hole, or at least not much of one.
iii) Groups of stars come in such an amazing range of sizes and shapes that it’s tricky to just say galaxy. So, astronomers sometimes use the presence of a central super-massive black hole to define whether or not something is a galaxy. They also often use the presence of dark matter to define if something is or isn’t a galaxy.

i) On that scale (time needed for the fusion), looks like life on habitable planets would only be affected if the churning results in unwelcome visitors (i.e. another star, planetoid with enough mass to disrupt orbits, or a black hole). With a civilization of our technology level, how much would be observed (or even noticed at all?)? This is all hypothetical pondering, mind, I’m aware there’s no hard data readily available.

ii) Well, that explains whether our Galaxy get to keep its arms when it gets absorbed into Andromeda! Do dwarf galaxy not count as ‘real’ galaxies in terms of supermassive black hole + dark matter content, then?

iii) Let me rephrase the question, then XD What’s the minimum mass for a black hole to be declared ‘supermassive’? Or better, what’s the SMALLEST supermassive black hole observed? Is there a rough estimate for the dividing line of ‘inferred’ dark matter mass for a collection of star systems to be declared a galaxy?

i) The big thing that living things would have to worry about is a sudden increase of star formations, which means a sudden increase in super novas, which sterilize big chunks of the galaxy around them. Even during a merging stars are very far apart.
ii) Not sure about the general definitions. Galaxies can vary so widely that defining one type vs. another is about as ad hoc as defining “blueness”.
iii) Same issue. But generally they have the mass of thousands of stars, instead of the mass of just one or two.

If a black hole absorbs so much matter that it grows as a giant supermassive black holes, can it undergo re-collapsing again as when it was once a star? If not, what’s preventing them from collapsing again? And what’s the deal with white hole and Hawking radiation?

There’s a post here that talks about that a bit, but the short answer is; falling into a black hole is pretty unhealthy. Even if you survived falling in, you’d be dead in short order when you get to the singularity inside.

I have read that these black holes are the endings of tunnels. There are always endings to tunnels and they always look like holes. I have read that these tunnels go into other dimensions or frequencies. These tunnels are the routes we take to get from one dimension to another.
I have read that we are energy beings that when choosing to be born here form tunnels, then plop–out we are born through a “black hole.” Seems logical to me that all holes are entering and leaving places and can be in all colors.
Saw a documentary where a pilot saw a tunnel formation open up in front of him. He was at the “hole” opening, and then flew through to the other end and left through another hole.
Do tunnels just seem to collapse? And would that be after they are used and not needed anymore?

I have read that these black holes are the endings of tunnels. There are always endings to tunnels and they always look like holes. I have read that these tunnels go into other dimensions or frequencies. These tunnels are the routes/what we form to get from one dimension to another.
I have read that we are energy beings that when choosing to be born here form tunnels, then plop–out we are born through a “black hole.” Seems logical to me that all holes are entering and leaving places and can be in all colors.
Saw a documentary where a pilot saw a tunnel formation open up in front of him. He was at the “hole” opening, and then flew through to the other end and left through another hole.
Do tunnels just seem to collapse? And would that be after they are used and not needed anymore?

@Jim
bit of both. most likely they were referring to the holographic principle, which is (in my opinion) a large stretch from its origins in hawking radiation. in the most basic sense the theory goes “information cannot be destroyed, and since black holes are maximally compact, any change in ‘information content’ would only persist within the shape of the black hole or its horizon in some form; the surface therefore captures all the information about bodies falling in, playing this simulation in reverse, you should get a surface who’s ripples interfere constructively and spit out matter”.

this is then extrapolated to mean that a 2 dimensional surface can fully encode 3 dimensional information. it isn’t as impossible as it sounds, you only need to look at space-filling curves and generalize the idea to higher dimensions. the catch is this 2d / 3d hologram of sorts would need to exist within as many dimensions as it encodes, regardless of the dimensionality of the ‘information medium’ (in this case the surface of a sphere; 2d topologically but can only be defined in 3d, just like a curved line is 1d but needs 2d to describe the curvature).

@phyllis
black hole tunnels, or wormholes for simplicity, could exist. the problem with them is that due to gravity of anything passing through it (matter, radiation, even vacuum expectation energy / ZPE itself) would force the edges of the hole together cutting them off – keeping it open is the challenge.

the second problem with ‘black holes are actual holes’ approaches is, you can’t ever escape. entering is fine, what do you exit, and how, if a black hole’s gravity is so massive that light cannot escape? white holes are a different story, separate article, more problems.

the third problem is there is absolutely no conceivable way to join two holes – any natural wormholes / tunnels would literally be the same one that spawned the alternate universe. otherwise you’re building two heaping gravity wells and ‘hoping’ they join up through a topology bypassing both universes, a feat requiring so much energy (nevermind coordination) we don’t see particles behaving this way even in theory.

for this reason i dislike ‘tunnel’ analogies for anything ‘hole’ related in spacetime. the connotation of ‘digging under’ often comes up, to which i say you’re at best using dirt to dig up dirt (see alcubiere drives) rather than building a proper tunnel.

What if the implosion of a star, resulting in the super-compression of its enormous mass, literally tears a hole in the fabric of time? Or perhaps, and this is purely speculation, black holes could eventually reach a critical mass, then explode to create a new universe? Of course, from earth we are only able to observe so much, so we can only hypothesize about the physics of a black hole from what we observe, millions of years after they happen because of the distance. It is entirely possible too, that the laws of physics as we know them do not apply in other galaxies, nor will we know unless we somehow get there to perform tests and firsthand observation. For now, then, we cannot say for certain whether black holes lead to a crushing end, or to a different dimension, so until then, the truth will be left to the imaginations of writers and astronomers.

how come we,well technically you, get to know that there is singularity inside a black hole.. when one has never been INTO a black hole.. maybe,maybe! there could be a chance of ‘reforming’ once matter has entered a black hole! as we see in much of science fiction traveling devices!
is there any chance of life in there! any possibility maybe!